It's funny, the list concept I've been toying with running the Centurion in a PHR fleet is basically exactly what you described, running two in a 1500pt list with 12 launch assets.

Looking at the firepower, here are my thoughts. On standard orders, against a single target, barring CA weapons, the Centurion is...not great, but that goes for most Heavy Cruisers, and the Centurion largely matches most of it's non-BTL heavy cruiser counterparts (i.e. Moscow, Onyx, Shenlong) there, with the PHR 8-shot broadsides being the exception. The broadsides can situationally give it a bit more standard orders oomph if going WF isn't worth it that it does have over the other Heavy Cruisers, it's an extra option if nothing else. On weapons free, against a single 3+sv target, it lacks damage relative to it's non-BTL Heavy Cruiser counterparts in an absolute sense (and will beat out something like a Hector that can't focus it's weapons on a single target), though matches pretty well in terms of cost efficiency given the 17-25pt price difference (it'll pretty well match a Moscow, and drag a bit behind a Shenlong and Onyx). Against two 3+sv targets (if the broadsides are lined up) it'll match or exceed the other non-BTL Heavy Cruisers pretty well in absolute terms and exceed them in cost efficiency, the big thing is that can't line that up with a target to the front with the broadsides making it more awkward to get that use out of it. The lack of CA weaponry is the big kick in the pants, and I think that's what hurts the most. I wish the gun was different and felt more like a big cannon than a rapid firing machinegun, but there's some use to the higher lock value I suppose.

Resiliency however is a bright spot, barring PD, though anything that would really make a big dent on it in one go isn't going to care too much about 2-3 extra PD anyway. Aside from that however, she's got as much HP as a Battlecruiser with a better armor save, meaning short of a Battleship, there's not much that's harder to kill. At the same time, she's cheaper than anything else in her category, making her very resilient for the points investment relative to other UCM and PHR ships. The Ceramic Armor penalty I don't think serves a balance purpose at this point and could probably go, and once crippled it's probably dead or trivially finished off most of the time anyway, but it's not something I think factors in much. Beyond that, it's as fast as any other Heavy Cruiser at 7", and has a pretty standard 6" sig.

I think it still needs some adjustment, but this is the best overall yet. I think the turret needs some buffing, especially to help that forward quarter, even if just on WF.

EDIT: as a thought, what if we went back to the original 3 damage concept. If the turret were something like 1 shot, Lock 2+ Damage 3 with Bloom and Fusillade 1, that would fit the visual concept a bit better I think, without having the Standard orders firepower of the original incarnation. Not sure how that should reflect in the cost, but may address some of the functionality issues. Maybe drop the lock to 3+ and drop Bloom?